Thermic telephone.



P. DE LANGE a; R. A. BARON VAN LYNDEN.

THERMIC TELEPHONE.

APPLICATION FILED NOVA. 1915.

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UETITED STATES PATENT OFFICE.

rm'rmz. n: LAiiGit Min Rosana: AERNOUT BARON van mmnmr, or nrrnaonr.NETHER- LANps, assrdtifoiis To n'AA'MLoozn vmvnoo'rscnar DENEDERLANDSCHE 'rnnnmm TELEPHOON MAATfiCiiAPPI-T, or UTBEGHT,NETHERLANDS, A COREORATION or mimnnanns.

To all whom it may concern:

Be it known that we, Pra'raa on Lance and RoanRrAaaNoU'rBAnoN VANLYNDEN, both subjects of the Queen of the Netherlands, and residing atUtrecht, in the Netherlands,have invented a new and useful Thermic Telehone, of which the fol- Ourxinvention relates to thermic telephones inwhich the sound is reproduced by means of a heating conductor. Theobject of our invention is to provide means through which the heatingconductor is enabled to stand a comparatively stron load or temporarilyeven an overload, without burning out 0W1 to overheating. This object weaccomplish by arranging a heat discharging body in contact with theexposed sound reducing portion of the heating conductor. en theheatingconductor is of some length, this heat discharging body may simutaneously be utilized to serve as a support for it and protect itagainst the damagmg influence of vibrations and the like. Inasmuch as itis rendered possible to overload the heating conductor without dangerofburning it out an improved reproduction of sound is attained ascompared with what would be attainable with the same apparatus butwithouta heat discharge.

Reference is to be had to the accompanying drawings in which we haveillustrated by way of example, an embodiment of our invention. Figure 1shows a thermic telephone in elevation, partly in section, drawn to anenlarged scale, Fig. 2 is a detail view of the support for the heatingconductors. The'telephone shown is designed to be directly introdii t'edinto the auditory passage of the hu n ear. It comprises a tubular casing1 provided with a sound opening 2 at the top and closed by a plug 3screwed into a thread 4 at its bottom. In the illustrated example, theheating conductor consists of an'arched heating wire, the exposedportion 5 of which serves as sound emitter. Its branches 7 are fixed ina sup ort 6 of insulating material, and connected to the currentconductors B and 9.

The heating conductor 5, 7 and its support '5 are covered by a cap 10,the interior 11 Specification of Letters Patent.

THEM/no TELEPHONE.

A a iieati'an flledfievembtr 4, 1915. Serial No. 59,628.

of which forms the sounding cnameel and communicates through an opening12 at. its top with the sound opening 2 of the casing 1. The upper partof cap cents against an annular flange 13 of casing 1 while its baseabuts against a flange it provided on the heating conductor support 6.The support 6 and the cap 10 are secured in place within the casing 1 bymeans of the screw plug 3 which presses against the support 6.

The heat discharge body 15-, according to our invention, is in contactwith the ex posed portion 5 of the heating conductor. It must possesssuflicient heat capacity to effectively cool the wire 5, 7 when itbecomes heated by current passing through it. On

the other hand, there must be no danger of shortcircuiting by thedischarger. The heat dlscharger 15 is either made of a semi-conductor,such as marble; or of a conductor such as metal, coated with a layer ofin-.

sulating material.

In the example illustrated. the heat dis charger 15 rests upon two studs16 on which it is held by screw nuts 17. The studs 16 are fixed to theheat conductor support 6. As the discharge! 15 is able to rc- :ive rnparatively great amounts of heat aid, 0\ ng to its large area, todischarge them rap 51y, a continuous and cilicient cooling action on theheating conductor is secured even with considerable loads ofcomparatively long duration.

\Vith a heating conductor consisting of a plurality of heating wires,the cooling may be efiected either means of a single heat dischargercommon to all the heating wires, or by means of a plurality of heat dischargers, the number, shape, and manner of arrangement of which has nobearing on the scope of our invention.

We have found by tests that the action of a heating conductorcoiiperating with a. discharger in contact with its sound emittingportion is not affected as compared with the action of a heatingconductor without a discharger. It follows that our heat diechargingdevice has no unfavorable influence whatever on the operation of thetelephone.

It is obvious that our invention is not limited to the precise structureillustrated,

in which various modifications may be made without thereby involving anydeparture from our invention.

I'Ve claim:

1. In a thermic telephone, the combination of a heating condi'ictor witha heat discharger in contact with the sound emitting portion of saidheating conductor.

2. In a thermatic telephone, the combination of a heating conductor, aheating conductor support, and a heat discharger, said heat diwzhargerbeing secured upon said support in a position in wliichsaid heatdischarger contacts with the sound emitting portion of said heatingconductor.

2. In a tlierniic telephone,;1the combination'of a heating conductor, aheating conductor support,'a pair of studs mounted upon said support,and a heat discharging hody secured upon said studs so as to be incontact with the sound emitting portion of said heatin conductor.

4. In a tiermie telephone, the combina- 'tion of a heating conductorWith a heat discharging body made of a semi-conductor, said heatdischarging body being held in contact with the sound emitting portionof said heating conductor.

5. A thcrmie telephone, comprising in combination, a heating conductor,a support for said heating conductor, a heat discharger held in contactwith the sound emitting portion of said heating conductor, means forsupporting said heat discharge-r upon said support for said heatingconductor, and a mounting for said latter support.

6. A thcrmic telephone comprising a heating conductor and aheat-discharging body having a non-conducting surface in contact withthe soundemitting portion of said heating conductor.

In testimony whereof, we have signed this specification.

PIETEB as LARGE. ROBERT amour BARON VAN LYNDEN.

